Cyanamide Research Articles

Effects of hydrogen cyanamide on antioxidant enzymes’ activity, proline and polyamine contents during bud dormancy release in Superior Seedless grapevine buds

The effect of hydrogen cyanamide (HC) on dormancy release, antioxidant enzyme’s activity and proline and free polyamine contents were investigated in ‘Superior Seedless’ grapevine buds. HC application caused a sharp decrease of catalase (CAT, EC 1.11.1.6) activity and a transient stimulation during the 5 days following treatment of peroxidase (POD, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11) activities. This coincided with an accumulation of total free polyamines, especially putrescine (Put). Proline content increased dramatically. There was a strong correlation between APX and POD activities and total free PAs and Put contents implying a possible stimulating effect of the latter compounds on these enzymes. These observations indicate that HC triggers an oxidative stress leading to bud endodormancy release. Afterward, as budbreak started, we observed a rapid proline and Put degradation; this could be responsible for reactivation of growth. Indeed, the decline in Put to (Spd + Spm) ratio, reported here, may be considered as a reliable biochemical marker of bud growth resumption.

Superação da dormência de cultivares de mirtileiro em ambiente protegido com cianamida hidrogenada e óleo mineral

O mirtileiro é uma frutífera de clima temperado que necessita de frio no outono/inverno. A insuficiência de frio pode provocar deficiente e desuniforme brotação e floração, com reflexos na produção. A pesquisa realizada na Universidade de Passo Fundo-RS, teve por objetivo estudar a superação da dormência de cultivares de mirtileiro (Georgiagem, Climax e Aliceblue) em ambiente protegido, tratadas em 25-07-2007 com cianamida hidrogenada (CH), nas doses de 0,52% e 1,04% (1% e 2% do produto comercial Dormex®), com a adição de 0,5% de óleo mineral (OM), comparando com plantas sem tratamento. As plantas encontravam-se no terceiro ciclo vegetativo e no primeiro de produção. O plantio foi realizado em 2005, no espaçamento de 0,7 m x 2,0 m, com irrigação por gotejamento. De acordo com os resultados obtidos, a aplicação no final de julho de CH + OM concentrou e uniformizou a floração e antecipou a brotação das cvs. Georgiagem e Clímax. A cianamida hidrogenada, nas concentrações de 0,52% e 1,04% (1% e 2% de Dormex®), combinado com 0,5% de óleo mineral, não teve efeito na porcentagem de brotação, mas reduziu a produção, evidenciando efeitos fitotóxicos.

ChemInform Abstract: An Efficient Hydration of Cyanamides to Substituted Ureas with Acetaldoxime as an Effective Water Surrogate.

ChemInform Abstract: An Efficient Hydration of Cyanamides to Substituted Ureas with Acetaldoxime as an Effective Water Surrogate.

태양열 소독시 유기물과 석회질소 병행 처리에 의한 딸기 시들음병균 방제

유기물, 석회질소, 요소 병행처리가 딸기 시들음병의 친환경적 방제인 태양열소독의 효과 증진여부를 밝히고자 논산딸기시험장의 비닐하우스에서 2006년과 2008년에 분석하였다. 딸기에서 분리한 Fusarium oxysporum f. sp. fragariae 7개 균주의 100% 치사시간은 <TEX>$45^{\circ}C$</TEX>에서 6.6일, <TEX>$50^{\circ}C$</TEX>에서는 5.1일이 소요되었고 100% 치사온도는 <TEX>$46.7{\pm}0.1^{\circ}C$</TEX>로 나타났다. 태양열 소독에 의해 유기물 처리구는 처리전보다 토양내 유기물 함량이 증가하였고, 석회질소 처리구는 산도, 유기물, 칼슘 함량이 증가하였으나 요소처리구는 차이가 없었다. 태양열 소독시 지온은 처리간에 차이를 나타냈으며 7월 30일부터 8월 10일까지가 가장 높았고(<TEX>$48.4\sim54.8^{\circ}C$</TEX>) 유기물+석회질소 처리구가 다른 처리구보다 <TEX>$3\sim4^{\circ}C$</TEX> 높게 유지되었다. 또한 토양내 시들음병균은 각 처리구 모두에서 사멸되었다. 시들음병 이병주율은 무처리는 2006년 20%, 2008년 13.3%의 발병율을 나타낸 반면 태양열 소독 처리구 모두에서는 시들음병 발생이 없었으며 처리간 유의성이 있었다. 따라서 딸기 시들음병 방제를 위한 유기물+석회질소를 병행한 태양열 소독 방법은 기존의 태양열소독방법을 보완하여 처리기간을 줄이면서도 효과적인 방법이 될 것이다. Field experiments were conducted to evaluate the effectiveness of soil solarization at the Nonsan Strawberry Experiment Station, Korea in 2006 and 2008. In in vitro tests, exposure times to achieve an <TEX>$LD_{100}$</TEX> of Fusarium oxysporum f. sp. fragariae were 6.6 days and 5.1 days at <TEX>$45^{\circ}C$</TEX> and <TEX>$50^{\circ}C$</TEX>, respectively. A 100% lethal temperature was <TEX>$46.7{\pm}0.1^{\circ}C$</TEX> for the same fungus. For field trials, solarization was conducted during the summer season using polyethylene mulch in a plastic house. The organic matter+calcium cyanamide+solarization treatment increased pH, organic matter, and calcium content compared to those before treatment in soil analysis, but no effect had an urea+solarization treatment. The temperatures at 10 cm depth were different in each treatment and the highest temperature was recorded from July 30 to August 10. The average temperature in organic matter+calcium cyanamide+solarization treatment at 10 cm depth was <TEX>$3{\sim}4^{\circ}C$</TEX> higher than that in all the other treatments. All solarization treatments reduced the soil population of F. oxysporum f. sp. fragariae at 100% in 2008 relative to the non-treated control. All solarization treatments reduced Fusarium wilt incidence to 0% in 2006 and 2008. The effect of organic matter+calcium cyanamide+solarization against F. oxysporum f. sp. fragariae indicates that there may be future alternatives to traditional solarization for disease control as well as reducing the time needed.

Expression analysis of phytochromes A, B and floral integrator genes during the entry and exit of grapevine-buds from endodormancy

A common molecular regulatory pathway that involves PHYA, PHYB and floral integrator genes CONSTANS (CO), FLOWERING LOCUS T (FT) and SUPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) has been suggested to participate in the regulation of photoperiod dependent processes such as flowering and dormancy. In grapevines (Vitis vinifera L.), decreasing photoperiod and low temperatures trigger the transition of buds into endodormancy (ED), a process that is accompanied by drastic changes in gene expression of VvPHYA and B in leaves. To analyse the relationship of VvPHYA, VvPHYB, and grape homologues of Arabidopsis floral integrator genes VvCO, VvFT, VvMADS8, with ED, a comparative expression analysis of these genes was performed in grapevine-leaves and buds before, during and after the transition of buds into ED. The expression of all the above genes in the bud-tissue, and the fact that photoperiod regulates differently the expression of VvPHYA and B in buds than in leaves, suggests that the bud might be an autonomous or semi-autonomous organ in perceiving and transducing the photoperiod signal. On the other hand, the coordinated down-regulation of VvFT in leaves and buds during the transition of buds into ED, and its subsequent up-regulation following the application of dormancy-breaking compounds, hydrogen cyanamide (HC) and sodium azide, suggests that VvFT could play a key role in stimulating bud-growth by repressing their entry into ED.

Short Exposure to Sublethal Heat Shock Facilitates Dormancy Release in Grapevines

A wet heat shock (WHS) treatment in a water bath at 50°C for 1 hr is a powerful stimulus for grapevine budbreak. However, this treatment is not feasible as a horticultural practice in commercial vineyards. The development of an effective horticultural dormancy release practice favors a short, intense heat shock that combines convenient application and effective stimulation of budbreak. Thus, the influence of heat shock temperature and duration on dormancy release of grapevine buds was studied. Results suggested that in both WHS and dry heat shock (DHS) treatments, increased temperature can compensate for shortened shock duration. In addition, it appeared that buds better tolerate DHS than WHS. Based on these results, we analyzed the effect of short and intense heat shock on budbreak. A DHS of 10 to 30 sec at the sublethal temperature of 150°C served as a powerful stimulus of dormancy release. This short shock induced production of acetaldehyde and ethylene from the buds, as follows application of hydrogen cyanamide. This similarity suggests that analogous mechanisms are activated by the short, sublethal temperature pulse and the commercially used chemical stimulus. The efficiency of short and intense heat shock, which has not been previously documented, will aid the development of a feasible and practical treatment in commercial vineyards.

An Efficient Hydration of Cyanamides to Substituted Ureas with Acetaldoxime as an Effective Water Surrogate

An Efficient Hydration of Cyanamides to Substituted Ureas with Acetaldoxime as an Effective Water Surrogate

Effect of hydrogen cyanamide, mineral oil and thidiazuron in combination with tip pruning on bud break, shoot growth and yield in ‘Bourjasotte Noire’, ‘Col de Damme Noire’ and ‘Noire de Caromb’ figs

Commercial fig production is relatively new to the Mediterranean-type climate Western Cape Province of South Africa. A lack of lateral branch development impedes tree structure development and therefore adequate yields of quality fruit. The chemical rest breaking agents, Lift ® (thidiazuron 3 g L −1) at 6%, Dormex ® (hydrogen cyanamide, 520 g L −1) at 4%, mineral oil at 4% and a combination of mineral oil and Dormex ® at 2% each were evaluated in a split plot design in combination with tip-pruning vs. no-pruning to overcome apical dominance and increase complexity (Experiment 1). During the 2008/2009 season, an additional investigation was conducted to evaluate the use of thidiazuron and hydrogen cyanamide for harvest scheduling (Experiment 2). Dormex ® at 3% and Lift ® at 6%, were applied to dormant trees on 30 June 2008, 3 August 2008, 15 August 2008 or 30 August 2008. In general, Lift ® can be used to increase the number of buds breaking in ‘Bourjasotte Noire’ and ‘Col de Damme Noire’, while tip pruning decreased bud break with a resultant increase in shoot length. Dormex ® and oil combined decreased bud break in these two cultivars but was effective on ‘Noire de Caromb’. Where bud break was increased the resultant N + 1 shoot length was decreased. RBAs increased the number of fruit in both the breba and main crop of ‘Noire de Caromb’, but decreased fruit size of the breba crop. Our data are not conclusive as to what the reason for low lateral bud break might be but leans towards strong AD in seasons with 400 Utah CU or more, but might include some delayed foliation response in seasons with less than 200 Utah CH.

Research on abatement measures of allelopathic autotoxicity of Rehmannia glutinosa

To explore effects on allelopathic autotoxicity of Rehmannia glutinosa of different abatement measures. The experiments for abating allelopathic effects of R. glutinosa were designed with the reducing rate as a indication, three measures of the treating soil with lime nitrogen, and water washing were employed, R. glutinosa- Achyranthes bidentata rotation system and using Achyranthes bidentata as green manure, and seedling transplant were also studied for the abatement effect. Effect of seedling transplant was the best, reducing rate of transplant and bare root transplant on the 20th day after emergence was 76.80%, 71.70%, respectively. The reducing rate of the treating soil with microorganism reached 54.25%. The effects of water washing and R. glutinosa-A. bidentata rotation system and using A. bidentata as green manure were not satisfied. Especially only using A. bidentata as green manure without rotation system worsened the allelopathic effects of R. glutinosa. All measures can abate allelopathic effects of R. glutinosa to some extent except only using A. bidentata as green manure.

Fe-based catalysts for oxygen reduction in proton exchange membrane fuel cells with cyanamide as nitrogen precursor and/or pore-filler

Fe/N/C catalysts for oxygen reduction reaction were synthesized via impregnation or ballmilling. The role of cyanamide (CM) as nitrogen precursor and/or pore-filler for a highly microporous carbon (Black Pearls 2000) was investigated. The use of CM in this work resulted in two main differences compared with phenanthroline from our previous work; (i) ballmilling the precursors did not result in improved activity of the resulting catalysts, and (ii) the activity after the first pyrolysis in argon was relatively high, but did not increase after a second pyrolysis in NH 3. These differences may be explained by TGA measurements of both pore-fillers, where complete gasification of CM is observed at temperatures above 750 °C in Ar, while pyrolysis of phenanthroline in Ar results in 20 wt% residual carbon-based material. Consequently, when using CM as pore-filler with a highly microporous carbon support, the maximum microporous surface area and nitrogen content is reached after only a single pyrolysis in Ar. The most active catalyst prepared with CM was obtained by pyrolysing in Ar at 950 °C a catalyst precursor containing 1 wt% Fe, 80 wt% CM and Black Pearls 2000. This catalyst possessed about 1/6th the catalytic activity of best reported using phenanthroline as a pore-filler. Changing the carbon support had effects on the activity and stability of the catalysts. The catalysts made with a non-porous furnace black (N330) or carbon nanotubes as a carbon support were more stable but less performing than those using carbon supports having high microporous surface area like Black Pearls 2000 or Ketjenblack. The desirable properties for a pore-filler molecule used in the synthesis of Fe/N/C-catalysts by the pore-filling method are discussed.

Effects of different forms of soil disinfection on soil physical properties and cucumber growth

Experiments were conducted to study the effects of three soil disinfection methods (ridge and furrow soil solarization with plastic film mulch, calcium cyanamid with stalk, dazomet fumigation) on soil physical properties and the growth of cucumber in greenhouse conditions. The results show that ridge and furrow solarization with plastic film mulch has no visible effect on soil physical properties. While the content of coarse silt decreases by 9.5% compared to CK, the contents of two diameter of sands (0.1～0.5 mm, 0.5～1.0 mm) increase by 39.4%, 117.7% respectively compared to CK. No significant changes are noted in the re-maining components. The content of clay in soil treated with calcium cyanamid and stalk increases by 163%, the contents two di-ameter of fine silts (0.001～0.005 mm, 0.005～0.01 mm) increase by 52.1%, 116.8% respectively compared to CK. Clay content of soil treated by dazomet fumigation decreases by 65.8%, the contents of two diameter of fine silt in soil decrease by 33.0%, 32.2% respec-tively compared to CK. Different soil disinfection treatments exert different inhibitions on soil aggregation. Calcium cyanamid with stalk treatment is most effective, followed by dazomet fumigation treatment. Ridge and furrow soil solarzation with plastic film mulch is least effective. The three soil disinfection treatments increase average plant height, leaf number, chlorophyll content and yield of cucumber. Ridge and furrow soil solarization with plastic film mulch not only significantly increases the biological indices of cucumber, but also promotes cucumber yield.

APPLICATION OF CHEMICAL PRODUCTS ON OVERCOMING THE ENDODORMANCY IN PEAR TREES IN REGIONS OF LOW COLD UNITIES

APPLICATION OF CHEMICAL PRODUCTS ON OVERCOMING THE ENDODORMANCY IN PEAR TREES IN REGIONS OF LOW COLD UNITIES

BUDBREAK INDUCTION IN APPLE TREES BY ERGER AND CALCIUM NITRATE APPLICATION

In mild winter climates, the budbreak promoters application is one of main management strategies used to decrease problems of insufficient winter chilling on temperate fruit trees. Despite of the high efficiency of some chemicals on budbreak induction, the high toxicity showed by these compounds is one problem related to its use. Erger, an organic nitrogen compound, combined with calcium nitrate, has a similar effect to that of hydrogen cyanamid, with the advantage of being less dangerous to the environment. The objective of this study was to evaluate the effects of Erger and calcium nitrate combinations on budbreak induction of ‘Imperial Gala’ and ‘Suprema’s Fuji’ apples. The experiments were carried out in Cacador, Santa Catarina, Brazil (26°46’S, 51°W), at 960 m a.s.l., during two growing seasons (2006/2007 and 2007/2008). The treatments tested were control, standard (mineral oil 3% + Dormex® 0.7%), and Erger + calcium nitrate at concentrations of 3, 5, and 7%. Full bloom date, axillary and terminal budbreak, fruit set, and mean fruit weight were evaluated. All Erger + calcium nitrate concentrations anticipated the full bloom date in relation to control treatment, but were not observed differences with mineral oil 3% and Dormex® 0.7%. The budbreak promoters increased significantly axillary and terminal budbreak and increasing the uniformity of budbreak. Fruit set was not affected by Erger + calcium nitrate concentration in relation standard treatment. The combinations of Erger and calcium nitrate showed similar uniformity and performance to mineral oil and hydrogen cyanamide on budbreak, showing to be an efficient alternative to budbreak induction in ‘Imperial Gala’ and ‘Suprema’s Fuji’ apples.

On Application of Ammonium Sulphate, Ammonium Nitrate and Calcium Cyanamid in Summer and the Resultant Increase of Nitrogen in Mulberry Leaves.

On Application of Ammonium Sulphate, Ammonium Nitrate and Calcium Cyanamid in Summer and the Resultant Increase of Nitrogen in Mulberry Leaves.

Garlic extract improves budbreak of the 'Niagara Rosada' grapevines on sub-tropical regions

In the regions with mild winters, usually the chilling requirements for bud dormancy release of grapevines are not fulfilled, and only the highly toxic products CaCN2 (calcium cyanamide) and H2CN2 (hydrogen cyanamide) are recommended in conventional viticulture for budbreak. The purpose of this study was to verify the effect of garlic extract on budbreak of 'Niagara Rosada' grapevines in two different vineyards. The highest dose of garlic extract (70mL L-1) showed a great potential for budbreak in organic production, presenting similar effects of cyanamides in budbreak. This treatment improved the sprouting percentage, number of clusters, accelerated the beginning of sprouting and reduced the cycle between pruning and harvest.

Garlic extract improves budbreak of the 'Niagara Rosada' grapevines on sub-tropical regions

In the regions with mild winters, usually the chilling requirements for bud dormancy release of grapevines are not fulfilled, and only the highly toxic products CaCN2 (calcium cyanamide) and H2CN2 (hydrogen cyanamide) are recommended in conventional viticulture for budbreak. The purpose of this study was to verify the effect of garlic extract on budbreak of 'Niagara Rosada' grapevines in two different vineyards. The highest dose of garlic extract (70mL L-1) showed a great potential for budbreak in organic production, presenting similar effects of cyanamides in budbreak. This treatment improved the sprouting percentage, number of clusters, accelerated the beginning of sprouting and reduced the cycle between pruning and harvest.

Effect of 9-Hydroxy-10-oxo-12(Z), 15(Z)-octadecadienoic Acid (KODA) on Endodormancy Breaking in Flower Buds of Japanese Pear

The effect of 9-hydroxy-10-oxo-12(Z), 15(Z)-octadecadienoic acid (KODA) on endodormancy breaking was studied in flower buds of japanese pear (Pyrus pyrifolia Nakai). The optimal concentration of KODA (100 μM) for endodormancy breaking was established over a 2-year period during the endodormancy stage of 2006 and 2007 in japanese pear cultivars Kosui, Natsushizuku, and Hosui. The effect of KODA on endodormancy breaking in flower buds was similar between ‘Natsushizuku’ and ‘Kosui’ but somewhat lower in ‘Hosui’. These results indicate that KODA can be an effective agent for promoting endodormancy breaking of flower buds in ‘Natsushizuku’ and ‘Kosui’. Although not as effective as hydrogen cyanamide, KODA may be preferable at late endodormancy stages because it has no apparent phytotoxicity.

ChemInform Abstract: Synthesis of Reversed C‐Nucleosides

Abstractvia reactions of push‐pull activated aminomethyleneulose (I) with o‐phenylenediamine, cyanamide or 3‐oxoglutarate, respectively

Effects of Hydrogen Cyanamide on the Floral Morphogenesis of Kiwifruit Buds

The influence of hydrogen cyanamide (HC) on the flower bud development of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang & A.R. Ferguson). �Hayward� was studied. The bud samples were taken every 5-10 d starting from dormant season (March) and fixed in FAA (10% formalin, 50% ethanol, 5% glacial acetic acid). Flower bud development was compared in three HC concentrations and the control. 1%, 2%, and 3% of HC was applied 35 d before the expected natural bud break. During the onset of bud break, only 57.6% of control buds had sepal primordia developed. On the other hand, HC treated buds had almost completed their stamen formation and started stigma primordia. When the control vines were in advanced bud break, gynoecial plateau already began to form in the vines treated with 2 and 3% HC. Vines treated with 1% HC lagged a little behind and had not started developing the gynoecial plateau. As the bud developed from the open cluster to the tight bud stage, the differences between the control and HC treated plants were more distinct. However, there were no differences between HC treatments as the ovule initiation took place in the buds.

REST BREAKING AGENTS ON APPLE ENDODORMANCY RELEASE UNDER SOUTHERN URUGUAYAN CONDITIONS

Apple (Malus domestica Borkh) commercial production in Uruguay is mainly located in the southern area (35°SL), where winter conditions not always satisfy chilling requirements for adequate sprouting. Limitations as poor budbreak percentage and extended flowering period are usually overcome with rest breaking agent sprays. In the present work, we evaluate the response of four apple cultivars ('Royal Gala', 'Granny Smith', 'Red Chief' and 'Fuji'); to four or five rest breaking product sprays in three moments, during 2005 and 2006. A factorial experiment with two factors, product per moment, was applied. The products applied were: hydrogen cyanamide (1.25%), paraffin mineral oil (3.0%), paraffin mineral refined oil (2.0%) in all cases; and hydrogen cyanamide (0.75%) + paraffin mineral oil (2.0%) combination on 'Red Chief' (2005 and 2006), 'R. Gala' and 'Fuji' (2006). The first application was performed considering 250 CU (UTAH model) registered from sensors located in the trees (first 15 days of August). Following applications were performed on the first and third week of September. Budbreak percentage on field conditions was evaluated weekly. Bud type (reproductive or vegetative), position (lateral or apical) and branch age were registered. In addition, shoot length was quantified. At harvest, flesh firmness, soluble solid and starch contents were measured. For most cases, 'moment × product' interaction and the main 'product' effect on bud break were not significant, while the main 'moment' effect had high significance. Treatments applied at the second and third moment showed a significant rise in budbreak percentage, regarding the control; while treatments applied at the first moment, had precocious budbreak. Hydrogen cyanamide applied alone or combined in 'Royal Gala', also accelerated fruit ripening.